Study On Physical And Numerical Simulation Of The Over-Dam-Flow

In the modern hydraulic engineering construction, baffle of the rapid flood and the atomization following it is the most important problem in a high-head power station and ensure it safety in operation. The atomized rain formed by rapid flood has a big impact on the power station. The principal factor influence the diffusion of atomized-flow is the over-dam-flow, and the serious zone of the atomized rain is in the vortex zone behind the dam, so, it is significant to study the motion of over-dam-flow and accurately predict the vortex zone.This paper bases on nationality naturalness science fund item, research of area of the atomized rain. the fund number is 50539060. The primary coverage of this paper is: firstly, gave a brief descriptive on the over-dam-flow,atomized rain,backward-facing step and relating basic theory in the paper, then introduced the research procedure of the physical test and results: The physical test has done in wind tunnel, the test model was made based on dates of the prototype measurements of er-tan hydropower station, and the prototype measurement has done by the Institute of Hydraulic and Hydroelectrically of China in 1999. The test results indicate that the height hole model's and the middle hole model's regurgitation zone length is 6.53～7.6 and 5.87～6.8 fold of the dam height respectively, it seems that the draw mode has a impact on the over-dam-flow. This preliminarily indicates that it is feasible to study the atomized rain and over-dam-flow in wind tunnel; Numerical simulation was done based on FLUENT, use Realizableк-εturbulent model simulated the over-dam-flow in the same geometry model and work conditions as the physical test. The simulation results prove that also the result a few bigger then the physical test, the numerical result is consistent with the test, and the numerical simulation is feasible in model the over-dam-flow. At last, we studied the flow in different Reynolds number under the same numerical method, analyzed the variations of the regurgitation length and the vortex center based on the variation of the Reynolds number. At the same time, as the over-dam-flow is similar to the backward-facing step flow in some case, we also give a comparison on the two flows in this paper.